The present invention relates to a method of manufacturing a semiconductor chip in which a wafer having a semiconductor region on a surface thereof is diced so as to be divided into a plurality of chip.
FIGS. 2A and 2B are diagrams showing a conventional dicing process using an outer peripheral blade saw. FIG. 2A is a cross-sectional view of the conventional dicing process, and FIG. 2B is a perspective view thereof.
A wafer 3 on which a semiconductor integrated circuit is patterned is disposed on a dicing table 4 through an adhesive tape 1. The wafer 3 adheres to the adhesive tape 1. The adhesive tape 1 is adsorbed by the dicing table 4 under a vacuum. The adhesive tape 1 is extended between ring-shaped frames 2. A dicing saw 6 is made up of a fred having diamond abrasive grains fixed onto an outer peripheral portion of a doughnut-shaped metal disc. The dicing saw 6 scribes the wafer 3 in such a manner that the dicing saw 6 is moved along a scribe line in a rotating direction while it is rotated at high speed in a direction C and is perpendicularly brought in contact with a plane of the wafer 3. After one scribe line is scribed, the table 4 is moved in a direction A by a pitch length of the scribe lines, and then a succeeding scribe line is scribed in the same manner. Cut grooves are formed in the wafer through scribing. The respective scribe lines are sequentially scribed into cut grooves 20-1, 20-2 . . . 20-7 one by one, thus cutting all of the scribe lines in an X-direction. Then, the table 4 is rotated at 90.degree., and scribe lines in a Y-direction are sequentially cut into cut grooves 21-1, 21-2, . . . one by one in the same manner.
All of the scribe lines in the X-direction and the Y-direction are cut so that an integrated circuit formed inside of the scribe lines is divided into a plurality of chips.
However, the conventional method of manufacturing the semiconductor chip suffers from problems stated below.
(1) Because the diamond abrasive grains fixed onto a blade in the outer peripheral blade saw are severely worn out, the blade must be frequently replaced by a new one. Also, because a cut-into speed must be made low, the cutting efficiency is remarkably low.
(2) Because the thickness of the blade is thick, between 30 to 50 .mu.m, the width of the scribe line increases to about 100 .mu.m. Because the width of the scribe line region is large, the number of intergrated circuits patterned on the surface of the wafer cannot be increased. That is, the chip costs are increased.
(3) In the case of dicing by the outer-peripheral blade saw, a broken portion is produced on the wafer in the vicinity of the cut surface. Also, because a length of the broken portion is long, a distance between the scribe line and a transistor of the integrated circuit must be made long. Therefore, the size of the integrated circuit is increased with the result that the chip costs cannot be lowered.